scholarly journals Active Galactic Nuclei: Sources for ultra high energy cosmic rays?

2009 ◽  
Vol 190 ◽  
pp. 61-78 ◽  
Author(s):  
Peter L. Biermann ◽  
Julia K. Becker ◽  
Laurenţiu Caramete ◽  
Alex Curuţiu ◽  
Ralph Engel ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays

scholarly journals Planck Neutrinos as Ultra High Energy Cosmic Rays

2020 ◽  
Vol 29 (1) ◽  
pp. 40-46
Author(s):  
Dmitri L. Khokhlov
Keyword(s):  
Black Holes ◽  
Cosmic Rays ◽  
Standard Model ◽  
Active Galactic Nuclei ◽  
Planck Scale ◽  
Galactic Nuclei ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
The Standard Model

AbstractThe studied conjecture is that ultra high energy cosmic rays (UHECRs) are hypothetical Planck neutrinos arising in the decay of the protons falling onto the gravastar. The proton is assumed to decay at the Planck scale into positron and four Planck neutrinos. The supermassive black holes inside active galactic nuclei, while interpreted as gravastars, are considered as UHECR sources. The scattering of the Planck neutrinos by the proton at the Planck scale is considered. The Planck neutrinos contribution to the CR events may explain the CR spectrum from 5 × 1018 eV to 1020 eV. The muon number in the Planck neutrinos-initiated shower is estimated to be larger by a factor of 3/2 in comparison with the standard model that is consistent with the observational data.

scholarly journals ON ACCELERATION AND PROPAGATION OF ULTRA-HIGH ENERGY COSMIC RAYS

2009 ◽  
Vol 18 (10) ◽  
pp. 1583-1586
Author(s):  
MARTIN LEMOINE
Keyword(s):  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Large Scale ◽  
Gamma Ray ◽  
Galactic Nuclei ◽  
High Energy ◽  
Current Data ◽  
Type I ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays

This paper discusses the correlation reported in 2008 by the Pierre Auger Observatory (PAO) of the arrival directions of the highest energy cosmic rays with active galactic nuclei (AGN). It is argued that these correlating AGN do not have the power required to be the sources of ultra-high energy protons. This current PAO dataset is further shown to disfavor giant radio-galaxies (both Fanaroff–Riley type I and II) as sources of ultra-high energy protons. The current data thus likely point to the local large scale structure, in which the actual sources of ultra-high energy cosmic rays camouflage. Finally, it is shown that the last gamma-ray burst in Centaurus A could explain, through rescattering on the Cen A lobes, the apparent cluster of events in this direction.

scholarly journals On the acceleration of ultra-high-energy cosmic rays

2008 ◽  
Vol 366 (1884) ◽  
pp. 4417-4428 ◽  
Author(s):  
Federico Fraschetti
Keyword(s):  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
New Physics ◽  
Acceleration Process ◽  
Tennis Ball ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays ◽  
The Past

Ultra-high-energy cosmic rays (UHECRs) hit the Earth's atmosphere with energies exceeding 10 18  eV. This is the same energy as carried by a tennis ball moving at 100 km h −1 , but concentrated on a subatomic particle. UHECRs are so rare (the flux of particles with E >10 20  eV is 0.5 km −2 per century) that only a few such particles have been detected over the past 50 years. Recently, the HiRes and Auger experiments have reported the discovery of a high-energy cut-off in the UHECR spectrum, and Auger has found an apparent clustering of the highest energy events towards nearby active galactic nuclei. Consensus is building that the highest energy particles are accelerated within the radio-bright lobes of these objects, but it remains unclear how this actually happens, and whether the cut-off is due to propagation effects or reflects an intrinsically physical limitation of the acceleration process. The low event statistics presently allows for many different plausible models; nevertheless observations are beginning to impose strong constraints on them. These observations have also motivated suggestions that new physics may be implicated. We present a review of the key theoretical and observational issues related to the processes of propagation and acceleration of UHECRs and proposed solutions.

scholarly journals On active galactic nuclei as sources of ultra-high energy cosmic rays

2008 ◽  
Vol 388 (1) ◽  
pp. L59-L63 ◽  
Author(s):  
M. R. George ◽  
A. C. Fabian ◽  
W. H. Baumgartner ◽  
R. F. Mushotzky ◽  
J. Tueller
Keyword(s):  
Cosmic Rays ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
High Energy ◽  
Ultra High Energy ◽  
High Energy Cosmic Rays
Sign in / Sign up

Export Citation Format

Share Document